Equations were derived based on the principles of light reflection to optimize the height and angle parameters of the reflective board in real time and location. The optimized parameters were applied to enhance the light intensity inside the lean-to greenhouses in china. The calculated results were significantly correlated to the actual measurements. Therefore, the equations developed in this study can be used to optimize the design parameters for the reflective board in practice. Additionally, based on the derived calculation equations, the optimized ranges of height and angle parameters were calculated for setting reflective board from autumn to winter and spring at latitude 32-42° in China.